1. Field of the Invention
The present invention relates to a current regulating circuit and a light emitting diode device having the same, more particularly to a current regulating circuit for regulating current flowing to a light emitting diode and a light emitting diode device having the same.
2. Description of the Related Art
Referring to FIG. 1, a conventional light emitting diode device 900 is powered by an alternating current (AC) power source, and includes a light emitting diode (LED) 910 and a resistor 920, which has a temperature-insensitive internal resistance (see FIG. 2).
After a long duration of operation at a working temperature (Tw) higher than room temperature (i.e., 25 degrees Celsius), ageing of the LED 910 will cause an internal resistance thereof to vary, causing a voltage difference across the light emitting diode 910 to vary, which in turn causes a current flowing across the light emitting diode 910 to fluctuate. As a result, brightness of light emitted by the LED 910 becomes unstable, and durability of the LED 910 is reduced.